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ing A point estimate is the value from a sample that best approximates the param

ID: 2948089 • Letter: I

Question

ing A point estimate is the value from a sample that best approximates the parameter of interest. If the parameter is a difference of proportions, then the point estimate is the difference in the sample proportions a) Below are the results from a sample of 6,224 individuals from the year 1721 who were exposed to snallpox in Boston. Doctors at the time believed that noculation, which involves exposing a person to the dasease in a controlled form, could reduce the likelihood of death Inoculated Yes No Total Person did not die from smallpox 238 5136 5374 Person died from smallpox Total 6 844 850 244 590 6224 If you wanted to test if the people who were inoculated were less likely to die from smallpox than those who were not inoculated, the parameter would be the difference n proportioss between those who were and were not inoculated What would be the pount estimate? b) Here is?two-way table of those aboard the Trane on its fateful voyage, classified according to class of ticket and whether or not they sunned Class First Second Third Crew Total survived| 203| ?18| 178 | 212| 711 Died Total325 285 76S52201 122167 528 673 1490 If you wanted to test if second class passengers were more likely to survave than thurd class passengers, the parameter would be the difference in proportions between those two classes What would be the point estimane? Submit

Explanation / Answer

a)
proportion of those who were innoculated and died = 6/244
proportion of those who were not innoculated and died=844/5980

hence required estimate
=6/244-844/5980
= -0.11654695981

b)
proprtion of surviving given second class=118/285
similarly for third class= 178/706

hence required estimate
=118/285- 178/706
=
0.16191044182